Chemical products are used as additives for a variety of applications, e.g. to treat cooling water which is recirculated in the cooling systems of commercial heating ventilating and air conditioning (HVAC) systems. Most cooling water typically includes minerals that may induce scale or corrosion in the cooling system components as the water evaporates during the cooling process. In addition, undesired microbiological growth may occur in the cooling water over time. To deal with these concerns, chemical additives are typically added to the cooling water to inhibit scale formation, corrosion and/or microbiological growth.
Heating systems that use water to provide heat through radiation, e.g., steam heat and hot water heat, are also conducive to scale and corrosion accumulation in the system components. The build up of scale and other deposits throughout the system can reduce the water circulation through the boiler, pipes and radiators, thereby reducing the efficiency of the heating system.
Conventional HVAC cooling systems and most commercial heating systems typically use a ready-to-use liquid treatment product as an additive. This product is typically provided in large drums or totes and is added at a metered rate to the water by a dispensing system. However, the liquid product is typically expensive and difficult to use and transport. In particular, the ready-to-use product must be purchased, transported, and stored in large volumes to meet the requirements of typical heating and cooling systems. The large volume of product that must be stored takes up a great deal of space in a facility, and further poses a safety hazard due to the difficulty in handling large quantities of a liquid product.
It has been found, on the other hand, that substantial improvements may be obtained by using a reconstitutable concentrated product instead of conventional ready-to-use liquid treatment products. For example, Water Care 9575 solid concentrated product available from Ecolab Inc. is a granular or powder concentrate which may be added to a suitable quantity of water and stored in a 60 to 110 gallon day tank from which the resulting diluted product is dispensed. An agitator is used to initially obtain a uniform solution of dissolved product.
By "concentrated product" what is meant is a concentrated material (e.g., a solid, semi-solid, liquid, etc.) that is typically mixed with a diluent such as water to form a use dilution which may be a solution, a suspension, an emulsion, etc. The use dilution may be used as is, or may be further diluted (e.g., in an HVAC cooling system where the additive is diluted in the sump of a cooling system or in a heating system where the additive is diluted with the make-up water prior to addition to the system) or mixed with other materials.
The use of a reconstitutable concentrated product offers several benefits, most notably savings in cost, transport and storage since less concentrated product is required, the concentrated product is less expensive to transport and the product and its associated storage/dispensing equipment require less floor space in a facility. However, it has been found that it is difficult to reliably control the concentration of a concentrated product in a day tank because operators are relied upon to add the proper amount of concentrated product to the tank. If too much concentrated product is used, the product is wasted, and if too little is used, the resulting mixture may not be as effective. In addition, equipment costs are still relatively high due to the need for a day tank and an agitator to maintain a uniform concentration in the tank. Moreover, the day tank still requires a significant amount of floor space in a facility.
Therefore, a need exists for a dispensing system and method for dispensing a concentrated chemical product into water and other related applications which is safer, less expensive, easier to use and more controllable.